US 2014/0000537 discloses a handheld work apparatus with a combustion engine and a fan wheel for conveying cooling air for the combustion engine. The fan wheel is arranged in a fan wheel housing. The combustion engine has an injection valve for supplying fuel. The injection valve is arranged in a cooling region into which cooling air conveyed by the fan wheel flows via a connection opening in the rear wall of the fan wheel housing.
Fan wheel housings are usually realized in an approximately helical manner, the distance between the peripheral wall of the fan wheel housing and the rotational axis of the fan wheel increasing in the rotational direction of the fan wheel. An outlet, through which the cooling air flows from the fan wheel to the cylinder of the combustion engine, is usually provided at the end of the fan spiral. Conducting the cooling air, which has cooled the cylinder beforehand, subsequently to the muffler is known for cooling a muffler of the combustion engine. Such cooling air-guidance proceeds, for example, from U.S. Pat. No. 4,846,301.